Use of smart grid for a power network is growing rapidly to strengthen an electricity infrastructure, as a countermeasure to efficient energy use, reduction of carbon dioxide, and the like.
A smart grid is a next-generation power network, which is configured to execute bidirectional communication between the consumer side that uses electricity and the supplier side that supplies electricity via a communication network, and which is capable of monitoring an electricity use status and trouble information by the consumer side and the supplier side in real time, by incorporating ICT (Information and Communication Technology) in a power network.
Recently, there is developed a technology in which, in addition to large-scale power sources (nuclear power generation, hydro power generation, thermal power generation, etc.), distributed power sources (solar power generation, wind power generation, fuel cell, secondary battery, biomass power generation, etc.) as renewable energy are included in an electric system, and in which ICT manages and distributes them intelligently, and grasps an electricity supply-demand status and a system trouble status in real time, to thereby realize an efficient electricity operation.
Further, although there are proposed many communication methods of connecting the consumer side and the supplier side in a smart grid, a common communication standard is not set, and there are various communication standards, at present.
Meanwhile, it is needless to say that a communication infrastructure is important, and a communication infrastructure is extremely important when a disaster such as an earthquake, typhoon, fire, flood, or the like occurs.
When a disaster occurs, it is necessary to grasp disaster information as soon as possible, and to accurately share the information by residents and rescue teams, to thereby rapidly execute aid and recovery.
Specifically, because a heavy damage, which affects electricity and communication infrastructures that relate closely to our lives, may be a serious problem for peoples' lives and socioeconomic activities, immediate attention is demanded.
When a disaster occurs, it is necessary to grasp and inform disaster information rapidly and accurately at the early stage, i.e., within half a day or a day immediately after the occurrence of a disaster.
If it is not possible to grasp disaster information accurately, an electric vehicle, which can be a power source, cannot be mobilized to a power outage area, and an emergency vehicle such as an ambulance cannot be mobilized to aid victims, which may hinder rapid and efficient recovery and aid.
Further, even if a disaster information notification and disaster information sharing system employing ICT and the like are fully-equipped, they execute communication via an access point, which is a part of a basic communication path, most of the time, there is a limit to an alternate communication path in a case where a basic communication path is broken when a disaster occurs, and they thus have no meaning when a major disaster occurs.
After all, a rescue team goes to a site and confirms a disaster status, and people transmit information. That is, it cannot help but rely on people's action, which is a heavy drag on aid activities and recovery activities.
In view of this, in a case of disaster, it is necessary to secure an information transmitting/receiving means by supplying electricity to a communication device, which transmits/receives information.